Andy Midwood

Honorary Associate
Environmental and Biochemical Sciences
T: +44 (0)344 928 5428 (*)

Andy Midwood is a Honorary Associate of the Environmental and Biochemical Sciences department. This group is comprised of chemists and biochemists; as well as biogeochemists and hydrologists, soil scientists and mineralogists. It has extensive analysis capabilities enabling work from the molecular level to an entire river catchment scale. The group is a regular host to visitors and collaborators from a worldwide network, and with staff and students is home to over 100 people.

Rising atmospheric CO2 levels, the uncertainties of climate change and how all of this impacts the natural environment frames Andy’s research. He has over the last 20 years used a wide range of stable isotope applications to study soil-plant interactions and has focused particularly on soil carbon dynamics in an effort to understand how this huge terrestrial pool of carbon will respond to the changing world in which we live.

As a postdoc with Professor Tom Boutton’s Group based at Texas A&M University, he used a natural C3/C4 transition created by woody plants encroaching into a natural savannah grassland in south-west Texas to initially study soil C dynamics.

More recently working with Professor Pete Millard he developed a natural abundance 13C isotope technique to study the evolution of CO2 from soils. Broadly speaking this efflux can be divided into autotrophic respiration: that associated with plant roots and the rhizosphere, which is directly fuelled by plant derived C and heterotrophic respiration which is associated with the turnover of older C associated with organic matter. Being able to partition this efflux is potentially very powerful and allows a better understanding of the long term carbon status of a soil.

Andy has active links with a number of colleagues across the world including Pete Millard, David Whitehead and John Hunt at Landcare Research in New Zealand; Melanie Jones and Kirsten Hannam at the University of British Columbia, Okanagan and Denise Neilsen at Ag Canada in Summerland. With Professor David Robinson at University of Aberdeen he co-supervises two PhD students.

He is a Chartered Chemist and Member of the Royal Society of Chemistry, Member of the American Geophysical Union and an honorary reader at the Robert Gordon University where he lectures on mass spectrometry.


Books / chapters

  • Midwood, A.J. (2008) Stable isotope methods for estimating the labile metal content of soils., In: Willey, N. (ed.). Phytoremediation: Methods and Reviews., Humana Press, New Jersey, Methods in Biotechnology 23, 149-159.

Conference papers

  • Midwood, A.J., Paterson, E. and Thornton, B. (2002) Steady-state 13C labeling of Lolium perenne (ryegrass): comparison of plant with root exudate isotope signatures., The 9th Canadian Continuous-Flow Isotope Ratio Mass Spectrometry Workshop, University of Newfoundland, St John’s Newfoundland, August 25-28, 2002, p3.8
  • Midwood, A.J. and Proe, M.F. (1998) Use of 26Mg and 41K as tracers of mineral uptake in Scots Pine., 23rd Annual Meeting of the British Mass Spectrometry Society, University of Warwick, 13-16 Sept. p104.

Conference posters / abstracts

  • Craig, C-A.; Lilly, A.; Midwood., A. J.; Thornton, B.; Green, G. (2022) How variable are Sr isotope ratios in soil associations? – implications for extrapolating isoscapes, Joint European Stable Isotope Users Group Meeting, 10-14 October 2022, Kuopio, Finland
  • Neilsen, G.H.; Hannam, K.D.; Neilsen, D.; Midwood, A.J.; Millard, P. (2012) Late-season foliar urea applications can increase yeast assimilable N in wine grape must (Vitis vinifera)., The 13th Annual Enology and Viticulture Conference, Penticton Trade and Convention Centre, 273 Power Street Penticton, BC Canada, 16-17 July 2012.
  • Neilsen, G.; Neilsen, D.; Hannam, K.; Millard, P.; Midwood, A. (2012) Foliar urea applications can increase berry yeast assimilable N in wine (Vitis vinifera L.) grapes., The VII International Symposium on Mineral Nutrition of Fruit Crops, Chanthaburi, Thailand, 19-25 May 2012.
  • Mayor, D.J.; Gray, N.; Elver-Evans, J.; Midwood, A.J.; Thornton, B. (2011) Copper contamination in marine sediments: implications for ecosystem functioning., MASTS Annual Science Meeting 2011, Science to Underpin Scotland’s Marine Plan, Herriot Watt Conference Centre, Edinburgh, 22-24 August 2011.
  • Thornton, B.; Midwood, A.J.; Coull, M.C.; Hudson, G. (2011) Carbon and nitrogen isotopes of scottish soils., Stable Isotopes Mass Spectrometry User Group Meeting 2011, Lancaster Environment Centre, Lancaster, 23-24 November 2011.
  • Hunt, J.E.; Millard, P.; Midwood, A.; Whitehead, D. (2010) Using natural abundance of delta13C to partition ecosystem soil respiration., Stable Isotope Fluxes in Carbon and Water Cycles of Terrestrial Ecosystems, American Geophysical Union Annual Reseach Meeting, San Fransisco, 12-18 December 2010.
  • Gray, N.; Thornton, B.; Midwood, A.J.; Mayor, D.J. (2010) Shifts in the natural abundance delta 13C signatures of estuarine PLFAs with increased copper., Joint Meeting of SIMSUG 2010 and ISO-SIG, Exeter University, 27-30 April 2010.
  • Thornton, B.; Zhang, Z.; Mayes, R.W.; Midwood, A.J. (2010) Can GC-C-IRMS quantify organics?, Joint Meeting of SIMSUG 2010 and ISO-SIG, Exeter University, 27-30 April 2010.
  • Thornton, B.; Hogberg, M.N.; Keel, S.G.; Metcalfe, D.B.; Gottlicher, S.G.; Betson, N.R.; Campbell, C.; Schindlbacher, A.; Hurry, V.; Lundmark, T.; Linder, S.; Midwood, A.I.; Nasholm, T.; Hogberg, P. (2009) Tracing photosynthate carbon from the tree canopy to forest soil micro-organisms., Stable Isotope Mass Spectrometry Users Group Meeting, University of Glasgow, 14-15 January 2009.
  • Hogberg, M.N.; Keel, S.G.; Metcalfe, D.B.; Gottlicher, S.G.; Betson, N.R.; Campbell, C.; Schindlbacher, A.; Hurry, V.; Lundmark, T.; Linder, S.; Thornton, B.; Midwood, A.; Nasholm, T.; Hogberg, P. (2008) Tracing photosynthate carbon from the tree canopy to forest soil microorganisms., International Symposium on Microbial Ecology (ISME -12), 12th, Cairns, Australia, 17-22 August 2008. Abstract.
  • Whitehead, D.; Millard, P.; Midwood, A.J.; Barbour, M.M.; Hunt, J.; Rogers, G.; McSeveny, T. (2008) Partitioning sources of soil respiration in an undisturbed forest ecosystem., Carbon: Global Cycle to Regional Budget, Royal Society of New Zealand, Wellington, New Zealand, 14-15 April 2008.
  • Thornton, B.; Gebbing, T.; Midwood, A.; Paterson, E. (2007) Application of compound-specific 13C-IRMS to trace the fate of plant-derived C in soil microbial communities., Stable Isotope Mass Spectrometry User Group (SIMSUG), University of Newcastle, 20-22 June 2007.
  • Sommerkorn, M., Barbour, M., Midwood, A., Hunt, J., Millard, P. and Whitehead, D. (2004) Ecosystem respiration, soil respiration: Can we partition them with S13C, S180, of CO2? Case studies in New Zealand., Abstract volume of SIBAE BASIN Joint Conference, Interlaken, Switzerland, 1-3 April 2004.
  • Thornton, B.; Paterson, E.; Midwood, A.J.; Sim, A.; Pratt, S.M. (2003) Assessment of the contribution of current assimilation in supplying carbon to root exudates of Lolium perenne using steady-state 13C labelling., In: Comparative Biochemistry and Physiology, Abstracts of the Annual Meeting of the Society for Experimental Biology, Southampton, 31 March – 4 April 2003. Volume 134/A (Suppl.), pS165.
  • Ayoub, A.S.; McGaw, B.A.; Shand, C.A.; Midwood, A.J. (2001) A comparison between soil extraction and isotope exchange methods for the determination of bioavailability of Cd and Zn., Stable Isotope Mass Spectrometry Users Group 2001 (SIMSUG), Glasgow, UK. Abstract.
  • Ayoub, A.S.; McGaw, B.A.; Shand, C.A.; Midwood, A.J. (2000) Stable isotope exchange: a new method to determine the plant availability of zinc in soil., Scottish Root Group Meeting. Macaulay Land Use Research Institute, Aberdeen, 15 November 2000.
  • Midwood, A.J., Boutton, T.W. and Archer, S.R. (1998) S2H and S180 of plant and soil water in a subtropical savanna parkland: Vertical stratification of soil water acquisition and plant response to rainfall., Application of Stable Isotope Techniques to Ecological Studies, Meeting Proceedings, Environment Canada, Saskatoon, Canada, 1998.
  • Midwood, A.J., Boutton, T.W. and Archer, S.R. (1996) Hand 18O indicate plant water use patterns in a subtropical savanna ecosystem., Stable Isotopes and the Integration of Biological, Ecological and Geochemical Processes. Proceedings, Association of Applied Biology, University of Newcastle.
  • Midwood, A.J.; Bacon, J.R.; Harthill, J.J (1995) Automated ion exchange system for sample purification prior to analysis by a thermal ionisation mass spectrometer., Inaugural Meeting of the Stable Isotope Mass Spectrometry Group, University of East Anglia, Norwich.